Recently, electronic components have been attracting attention and developed for practical use, in which a so-called MEMS (micro electronic mechanical system) is formed on main faces of semiconductor substrates made of silicon wafer or other materials by application of processing techniques for forming fine wiring lines of elements in semiconductor integrated circuits and the like.
Trial production and development of this sort of micro electronic mechanical system is carried out in a very wide range of fields including accelerometers, pressure sensors, actuators, and other sensors, as well as micromirror devices and optical devices having movable micromirrors.
FIG. 9 is a cross-sectional view showing a configuration example of an electronic component on which this sort of micro electronic mechanical system is formed and a conventional electronic apparatus in which this electronic component is hermetically sealed. As shown in FIG. 9, an electrode 123 for supplying electric power to a micro electronic mechanical system 122 or for sending electrical signals from the micro electronic mechanical system 122 to an external electric circuit is formed so as to be electrically connected to the micro electronic mechanical system 122, on a main face of a semiconductor substrate 121 on which the micro electronic mechanical system 122 is formed. The semiconductor substrate 121, the micro electronic mechanical system 122, and the electrode 123 constitute one electronic component 124.
An electronic apparatus is formed by accommodating the electronic component 124 in a recess A for accommodating an electronic component, which is contained in a package for accommodating an electronic component (hereinafter, also simply referred to as a ‘package’) 131, connecting the electrode 123 of the electronic component 124 via a conductive connecting member such as a bonding wire 133 to an electrode pad 132 of the package 131, and then placing a lid 134 over the recess A of the package 131 to hermetically seal the electronic component 124 in the recess A. In this case, the electronic component 124 has to be hermetically sealed in such a manner that an internal space is kept therein, in order not to disturb the operation of the micro electronic mechanical system 122.
In this electronic apparatus, when a wiring conductor 135 that has been formed so as to be extended from the electrode pad 132 of the package 131 to the external surface is connected to an external electric circuit, the hermetically sealed micro electronic mechanical system 122 is electrically connected via the electrode 123, the bonding wire 133, the electrode pad 132, and the wiring conductor 135 to the external electric circuit.
This sort of electronic component 124 is produced by arranging a plurality of micro electronic mechanical systems 122 in a matrix on a main face of a semiconductor mother substrate having a large area, and dividing the semiconductor mother substrate into pieces. However, this method has a poor productivity in production of electronic apparatuses and is difficult to put to practical use. The reason for this is as follows. When the micro electronic mechanical systems 122 are separated by a dicing process or the like, the cutting process has to be performed after each electronic component 124 is protected, in order to prevent a powder formed by cutting the semiconductor mother substrate made of silicon or other materials from getting attached to the micro electronic mechanical systems 122 and damaging the micro electronic mechanical systems 122. Furthermore, each electronic component 124 has to be hermetically sealed individually inside the package 131.
A method has been disclosed for producing an electronic device on which the MEMS is mounted by application of a process for wafer level packaging (see Japanese Unexamined Patent Publication JP-A 2004-209585, for example). In the electronic device produced using this method, in a junction portion between a substrate on whose main face the MEMS is formed and a lid that is placed over the MEMS and joined to the substrate, an electrode connected to the MEMS is electrically connected to a wiring conductor of the lid. With this production method, an electronic device on which the MEMS is mounted can be efficiently produced at low cost.
Recently, the micro electronic mechanical system is used in, for example, radio frequency (RF) technologies. Thus, there has been a demand for further downsizing of an electronic apparatus that includes an electronic component containing a micro electronic mechanical system and an electronic component sealing substrate for sealing the micro electronic mechanical system.
However, in accordance with the above-mentioned downsizing, an electrical connection path through which an electrode electrically connected to the micro electronic mechanical system extends to an external electric circuit is positioned closer to the micro electronic mechanical system, and thus electromagnetic interferences are easily caused therebetween. Accordingly, there is the problem that reliability tends to be lowered by, for example, instability in the mechanical and electrical operation of the micro electronic mechanical system inside the electronic apparatus.
Furthermore, there is the problem that the characteristics of transmission of radio frequency signals passing through the electrical connection path may deteriorate due to the influence of noises caused by turning on and off an electric field for generating an electrostatic force or a magnetic field for generating a magnetic force when driving the micro electronic mechanical system.